418 Bulletin 47, United States National Museum. 



e. Anal fin moderate, of 15 to 25 rays; dorsal inserted nearly opposite ventrals. 



/. Scales with their posterior margins entire and rounded; intestinal canal of moderate 

 length. 

 g. Last ray of dorsal not produced. 



h. A r ertebr;e about 50 in number (46 to 5G); species of northern regions. 



i. Vomer with teeth; ventral scutes weak, ventrals below middle of dorsal; 

 vertebne 50 to 56. CLUPEA, 206. 



ii. Vomer without teeth. 



j. Ventral scutes very weak, the belly more or less rounded; vertebrae 

 about 52; ventrals under middle of dorsal. CLUPANODON, 207. 



jj. Ventral scutes strong, the belly compressed; vertebrae 46 to 50; ven- 

 trals below or slightly behind front of dorsal. 



Ic. Premaxillaries meeting at a large angle, so that the tip of upper 

 jaw does not appear to be notched; cheeks longer than deep. 



POMOi/OBtis, 208. 



Tck. Premaxillaries meeting in front at a very acute angle, so that the 



emarginate front of the upper jaw receives the slender tip of 



the lower; fore part of cheeks very deep, deeper than long; 



jaws toothless. ALOSA, 209. 



hh. Vertebra? about 42 (40 to 44); tropical species with the scales large and 



usually firmly attached; ventrals inserted under middle of dorsal ; adipose 



eyelid obsolete. SARDINELLA, 210. 



gg. Last ray of dorsal produced in a long filament; scales large, not firmly attached; 



otherwise essentially as in Clupanodon. OPISTHONEMA, 211. 



ff. Scales with their posterior margins vertical, and pectinate or fluted; head very large; 



no teeth; intestines elongate; herbivorous. BREVOOBTIA, 212. 



PRISTIGASTERINJE : 



ee. Anal fin very long, of more than 30 rays ; dorsal fin inserted behind ventrals. 



I. Teeth not all villiform ; both jaws with strong canines ; ventrals present, very small. 



CHIHOCENTRODON, 213. 



II. Teeth all villiform ; no canines. 



m. Ventral fins present. ILISHA, 214. 



mm. Ventral fins wanting. 



. Dorsal fin present, inserted behind front of anal ; belly not very convex in 



outline. 

 o. Maxillary not greatly produced backward, not extending behind eye. 



OPISTHOPTERUS, 215. 

 oo. Maxillary much produced backward, extending behind eye. 



ODONTOCNATHUS, 216. 



nn. Dorsal fin inserted in front of anal ; maxillary short ; abdomen excessively 

 convex in profile, so that the body is very deep. PRISTIGASTER, 217. 



203. JENKINSIA, Jordan & Evefmann. 



Jenkinsia, JORDAN & EVERMANN, new genus, (siolifera). 



Very small species, closely allied to Etrumeus, but with minute teeth and 

 a silvery lateral band ; the dorsal with less than eighteen rays, the ven- 

 trals inserted below or just behind it. American. (Named for Dr. Oliver 

 Peebles Jenkins, Professor of Physiology in Leland Stanford Junior Uni- 

 versity, in recognition of his work on the fishes of Mexico and the 

 Hawaiian Islands.) 



a. Dorsal inserted a little nearer caudal than tip of snout, the ventrals just behind it ; dorsal 

 rays about 16 ; anal 11. ACUMINATA, 680. 



aa. Dorsal inserted midway between snout and base of caudal; dorsal rays 14 ; anal 15. 



LAMPROTVENIA, 681. 



aaa. Dorsal inserted nearer snout than base of caudal ; dorsal rays 11 ; anal 17. STOLIFERA, 682. 



